Selective actuating mechanism for percussive photoflash lamp array

ABSTRACT

For a photoflash assembly comprising a plurality of percussively-ignitable flashlamps mounted on a support member and arranged in a planar array with respectively associated reflectors and preenergized striker springs, a selective actuating mechanism for sequentially releasing the striker springs to fire respective flashlamps in response to successive indexing. The selective actuating mechanism comprises a single slidable bar retained in a longitudinal channel in the support member and having a number of linearly spaced projecting ramps. The lamps and striker springs are mounted in two parallel rows on each side of the channel with the strikers in each row projecting in opposite directions over the bar to lie in the path of travel of the ramps. Linear indexing of the slidable bar along the channel causes one of the ramps to release a striker. A detent retains the position of the bar after each indexing cycle, and the sequence of releasing the strikers in response to successive indexing is programmed by the number and respective location of the ramps along the length of the bar and the respective location of the strikers.

[ Mar. 5, 1974 i 1 SELECTHVE ACTUATING MECHANISM FOR PERCUSSIVEPHOTOFLASH LAMP ARRAY I75] lnventor: David R. Broadt, Lewisburg, Pa.

[73] Assignee: GTE Sylvanialncorporated,

Danvers, Mass.

1221 Filed: Dec. 18, 1972 1211 Appl. No.: 315,812

[52] US. Cl. 431/93 240/1.3, 95/11 L Primary Examiner Carroll B. Dority,Jr. Attorney, Agent, or Firm-Edward J. Coleman [5 7] ABSTRACT For aphotoflash assembly comprising a plurality of percussively-ignitableflashlamps mounted on a support member and arranged in a planar arraywith respectively associated reflectors and preenergized strikersprings, a selective actuating meehunism for sequentially releasing thestriker springs to tire respective flashlamps in response to successiveindexing. The selective actuating mechanism comprises a single slidablebar retained in a longitudinal channel in the support member and havinga number of linearly spaced projecting ramps. The lamps and strikersprings are mounted in two parallel rows on each side of the channelwith the strikers in each row projecting in opposite directions over thebar to lie in the path of travel of the ramps. Linear indexing of theslidable bar along the channel causes one of the ramps to release astriker. A detent retains the position of the bar after each indexingcycle, and the sequence of releasing the strikers in response tosuccessive indexing is programmed by the number and respective locationof the ramps along the length of the bar and the respective location ofthe strikers.

15 Claims, 6 Drawing Figures PATENTEI] MAR 51974 SHEET-1 0F 2 PATENTEDMAR 74 SHEET 2 0f 2 2 I 4 O 6 5 7 mz/Q W vantages of greater SELECTIVEACTUATING MECHANISM FOR PERCUSSIVE PHOTOFLASH LAMP ARRAY BACKGROUND OFTHE INVENTION This invention relates to multilamp photoflash units and,more particularly, to an array of percussivelyignitable photoflash lampswith means for selectively controlling the firing thereof.

The trend of photoflash devices has been toward the use of subminiatureflashlamps (an envelope volume of less than 1 cubic centimeter) incompact, disposable,

multilamp units to provide camera users .with the adconvenience,compactness and portability. A currently popular flashlamp unit of thistype is known generally in the trade as a flashcube, a specificembodimentof which is shown in U.S. Pat. No. 3,327,105, for example. Theunit comprises a set of four flashlamps,each with its own reflector,mounted socket on a camera. lnoperat'ion, the flashcube is sequentiallyrotated a quarter of a turn at a time, usually in response to eachoperation of the film advance mechanism of the camera, to successivelyplace unused lamps in a firing position facing theobject beingphotographed. Eachof the flashlamps consists of an hermetically sealed,light transmitting glass envelope containing a filamentary combustiblematerial, such as shredded zirconium foil, and a combustion supportinggas, such as oxygen. In thecase of flashcubes employing electricallyignited lamps, a pair of lead-in wires pass through the lamp envelope tosupport therein a filament in combination with globules of ignitionpaste. When the flashcube is in the firing position, segments of thelead-in wires disposed outside the lamp envelope are securely engagedwith electrical-contacts in the camera socket, which in turn areconnected by wires anda shutter actuated switch to the camera powersource, usually a pair of dry cell batteries. When a photographeractuates the shutter release mechanism to Tsnap a picture, he also, bythe same operation, closes the electrical circuit from the batteries tothe ignition system in the lamp to thereby flash thelamp. The timing ofthe ignition of the combustible material in the lamp issynchronized-with the exposure of the film by actuation of the shutterrelease so that efficient utilization of the light from the flashlampmay be obtained.

A not infrequent problem. that has been faced by the average amateurphotographer when using a battery operated flash system, however, hasbeen failure of the lamp to fire due to weak batteries and/or dirt orcorrosion on one or more of the electrical contacts in the system. Toovercome this problem and provide improved flashlamp reliability,percussive-type flashlamps have been developed which may be mechanicallyfired without the need for batteries. As described in U.S. Pat. No.3.535.063. for example. such flashlamps have a mechanical primer sealedin one end of the lamp in lieu of lead-in wires. This primer maycomprise a metal tube extending from the lamp .envelope and a charge offulminating material on a wire supported in the tube. Operation of thepercussive flashlamp is initiated by an impact onto the tube to causedeflagration of the fulminating material up through the tube to ignitethe combustible disposed in the lamp envelope. The percussivetype lampsare also produced in subminiature envelope sizes and are employed inpercussive flashcube units having respective preenergized strokersprings associated with each lamp, as described in U.S. Pat. No.

3,597,604.'The percussive flashcube is indexed into firing positionsimilarly to the electrical flashcube; however, the flashlamp to be usedis fired by the action 'of a member, associated withthe camera shuttermechanism, moving up through the flashcube base to release therespective preenergiz ed striker spring, whereby it sharply impactsagainst the primer tube of the lamp.

Another development in the field of multilamp flash units for providingadditional convenience and flexibility is the provision of a linear'orplanar array of flashlamps. In such an arrangement, a plurality of lampsface in the direction of the object being photographed v whereby it ispossible to rapidly switch from one lamp to another or to flash morethan one lamp at a time if additional light is required. Examples ofpreviously described flashlamp arrays are provided by the following U.S.Pat. Nos: 3,267,272, 3,430,545; 3,438,315;

3,454,756; 3,458,270; 3,473,880; 3,500,732; 3,544,251; 3,545,904;3,443,875; 3,552,896; 3,562,508; 3,598,984; 3,596,985; 3,608,451 and Allof these patents describe electrically energized flash systems with thesequence of lamp flashing being controlled by various electricalswitching means including: manually controlled spring slide contacts; arotary switch; thermally or chemically reactive switches placed inthermal proximity .to the flashlamps; a switch within each lamp envelopewhich closes in response to firing to prepare the next lamp in sequence;a voltage surge across the lamps causes ignition of only the lamp havingthe lowest voltage break down characteristics, bimetallic switches; ameltable junction within each lamp envelope; and solid state switchingcircuits. Although providing a number of advantages, the electricalarrays are still prone to the reliabilityproblems associated with anelectrical flash system, namely, ignition failures due to weak batteriesand/or dirty or corroded'electrical contacts.- 1

Another disadvantage of electrical arrays is the relative difflculty ofmaintaining the proper lamp firing sequence in the event the array isremoved from a camera and subsequently replaced. To overcome thisproblem, the prior art, as indicated above, employs special typeflashlamps or relatively complex momory circuits or switches in thecamera. Such approaches are generally considered undesirable withrespect to both cost and reliability. v

To overcome the "above-described disadvantages of electrical arrays, 21copending application Ser. No. 261,587, filed June 12, 1972 and assignedto the present assignee, describes a linear photoflash lamp arrayincluding a plurality of percussively ignitable flashlamps mounted in arow on a horizontal base, an array of reflectors, and a plurality ofpreenergized strikers releasable to fire the flashlamps. Each reflectorof the array. is radially disposed behind a respective lamp. The

and strikers. The slidable bar is provided with a number of linearlyspaced projecting ramps, and the strikers are mounted to project beyondthe periphery of the channel to-lie in the path of travel of the ramps.Linear indexing of the slidable bar along the channel cause one of theramps to release a preenergized striker and fire a respective-lamp, andsequentially lamp firing is effected by successive indexing of the bar.The sequence of releasing the strikers in response to successiveindexing is, programmed by the number and location of the rampsalongthelength of the bar.

In the specific embodiment described in the abovementioned copendingapplication, the photoflash assembly comprises two rows of percussiveflashlamps and reflectors facing in opposite-directions. A slidable baris required for each row of lamps and strikers; hence, the two rows oflamps and strikers are mounted on the base between two parallel channelscontaining slidable bars which move in opposite directions with respectto each other. Each ramp on a slidable bar is adapted to release arespective striker, and each successive ramp after the first is spaced D(n l).r from its pre'ceeding ramp in the striker sequence, where D isthe distance between strikers, n is the number of the .ramp in thestriker release sequence, and .r is the distance the slidable bartranslates during each indexing movement for release of a striker. Eachbar travels from left to right as viewed from its side of the array, butthe strikers are released from right to left. Accordingly, the two rowsof lamps are staggered and the reflectors are nested back-to-back toprovide a somewhat extended free end space in each channel into whichthe bar can move upon being indexed.

SUMMARY OF THE INVENTION The percussive array described in theaforementioned copending application is bidirectional and requiresrotation after expending the first row of lamps so as to place theremaining row of unused lamps into the firing position. In manyapplications it is desirable to use a mOre compact, planar array offlashlamps to enable rapid flashing of all lamps without rotation of thearray. v

' Accordingly, it is an object of the present invention to'provide animproved slide-bar actuating mechanism which is particularly suitablefor use in compact planararrays.

A further object of the invention is to provide a percussive flashlamparray which is economically and compactly packaged to provide increasedlight output and which does not require movement of either the lamps orthe array during the entire operating sequence.

1 mechanism comprising a slidable bar retained in a longitudinal channelin the support member which is located between and parallel to the tworows of strikers. .The slidable bar is provided with means forsequentially releasing the preenergized strikers to fire respectiveflashlarnps of the array in response to successive indexing of thebar'along the channel. In a specific embodi- BRIEF DESCRIPTION OF THEDRAWINGS This invention will be more fully described hereinafter inconjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of'the exterior of a multilamp photoflashassembly including features of the invention;

FIG. 2 is a plan view on an enlarged scale of the rear wall of the flashassembly of FIG. 1 with a slidable bar actuating mechanism according tothe invention and the several spring members shown in full and theseveral flash-lamps associated therewith shown in phantom;

FIG. 3 is an enlarged perspective of the flash assembly of FIG. 1 asviewed facing the base, with sections broken away to illustrate portionsof the interiorthereof;

FIG. 4 is a sectional view on line 4-,4 of FIG. 2 which is. somewhatenlarged and simplified to'more clearly show one of the spring membersand its position with respect to the slidable bar, and to show theaperture through the rear wall member;

FIG. 5 is an enlarged scale, somewhat schematic view of the slidable barin its channel with respect to the striker spring positions; and, I

FIG. 6 is a fragmentary detail of a portion of the bottom of theslidable bar of FIG. 5, illustrating the ratchet drive teeth.

DESCRIPTION 'OF THE PREFERRED EMBODIMENT In the specificembodimentillustrated in FIGS. 1-3, the photoflash assembly comprises a group ofeight axially disposed flashlamps 11-18 and associated coaxialreflectors 20 arranged in a compact planar array comprising two stackedrows of 4 lamps each. The array is housed in a box-like container 22comprising a substantially planar base member 24, a substantially planarrear wall, or support, member 26 secured to the rear of base 24 anddisposed substantially normal thereto, a pair of side walls 28 and 30,and a top wall 32. Members 24-32 maycomprise a unitary structure ofmolded plastic, or wall member 26 may be separately longitudinal axes ofthe lamp disposed normal thereto.

Also mounted on wall member 26 are eight preenergized striker springs41-48 each positioned in operative relationship'with a respective one ofthe lamps. Accordingly, the striker springs are arranged in two rows,the row 41-44 being associated with the row of lamps 11-14, and-the row45-48 being associated with the row of lamps -18. As will bedescribed'in detail hereinafter, the striker springs are individuallyreleasable to fire their respectively associated lamps.

Referring to FIGS 1 and 3, each concave reflector is disposed coaxiallyabout its associated tubular shaped lamp 11-18, with all reflectorsoriented to face in one direction away from the lamp mounting surface.Each reflector is essentially parabolic modified by the provision of 4flats 39 along the sides thereof. Adjacent flats of adjacent reflectorsabut one another to define a compact planar array of reflectors Thehairpin torsional section of'each of the springs 41-48 are disposed inthe clearance space between or about the reflectors.

The array of eight reflectors 20 may comprise a singlepreformed sheet 40of plastic material having alight reflective coating; for example, theinwardly dished reflect r surfaces 20 may be provided by vacuum forming.Toward the vertex of each reflector is provided a coaxial aperture 51 ofsuitable shape for fitting about the tubular flashlamp (see lamp 13 ofFIG. 3). If the radiation from a flashed lamp proves to be a problem bycausing sympathic ignition of an unselected lamp, the parabolicreflector skirt 20 may be extended back to cover substantially theentire lamp envelope, rather than-leaving an exposed portion asillustrated in FIG. 3. The overall package configuration of the lampreflector array may be similar to that described in the copendingapplication Ser. No. 260,271, filed June 6., 1972 and assigned to thepresent assignee, except for the type of selective actuating mechanismemployed and the arrangement of the pre-energized striker springs I Eachof the lamps 11-18 is substantially identical and comprises (see lamp 14of FIG. 3)v an hermetically sealed light-transmitting envelope 50 oftubular shape having a primer depending therefrom. A filling ofcombustible foil 52, such as zirconium, and a combustionsupportinggassuch as oxygen, are disposed in the envelope. The primer comprises ametal tube 54 coaxially projecting from the envelope and within which awire anvil and a charge of fulminating material are disposed. Each lampis supported on the wall member 26 to project normal therefrom, and thusaxially parallel to the base 24, by means of a respective bore 56 (alsosee FIG. 2) into which the primer tube 54 is inserted. That is, thereare two rows of four bores56 as shown in FIG.

Each of the preenergized striker springs 41-48 is substantiallyidentical and comprises a folded torsion device typically formed from0.021 inch music wire about 2.5 inches long. Referring to FIG. 4, andthe numerically identified elements Qof spring 42, the wire is shaped toform a hairpin torsional section having segments 58 and 60 joined by abight 62; The end portion Initially the striker 68 may be formed at anangle of about 90 to the stationary supporting foot 64, although theangle through which the striker is rotated to position it behind catch66, as shown, may be of any value that does not cause over stressing ofthe wire. The wall member 26 is shaped to provide a suitable bearingsurface 70 for the heel of the striker during cocking. This bearingsurface also aids in preventing accidental displacement of the springsufficiently to free the striker from the catch some time after cockingand before firing is intended.

Sequential displacement of each cocked striker 68, to release it fromthe catch 66 and thus permit it to strike the percussive primer. tube 54and tire the associated lamp, is effected by a selective actuatingmechanism in accordance with the invention. Referring to FIGS. 2-4, theactuating mechanism comprises a slidable bar 72 having five linearlyspaced projecting ramps 81-85 disposed along one side thereof. The bar72 is retained in a longitudinal channel 86 in wall member 26 which islocated between and parallel to the two rows of strikers 41-44 and45-48. Each of the cocked strikers 68 of the springs 41-48 projectsbeyond the peripheries of channel 86 to overlie a portion of theslidable bar 72. In particular the strikers of the row of springs 41-44project in a direction opposite that toward which the strikers of row45-48 project, with the free end of each striker 68 disposed to lie inthe of segment 58 is shaped to define a' stationary supporting foot 64,the tip of which is shaped to define a catch 66. The end of segment 60is shaped to define a striker 68, which when the spring is preenergized,or cocked, as shown, crosses over the supporting foot 64 and is retainedby catch 66. The stationary supporting foot 64 is seated in an elongatedslot formed in the wall member 26, the slot being sufficiently shallowso that the catch 66 formed in the free end of the foot 64 will projectabove the upper surface of the wall member 26.

path of travel of one ofthe ramps 81-85 on bar 72. Hence, upontranslationally indexing the bar 72 along channel 86, the strikeradjacent to an up-coming ramp (such as striker 68 of spring 45 isadjacent to ramp 8]) is pushed upwardly by the ramp a distancesufficient to clear the top of catch 66. The striker then swingsclockwise, as viewed facing the mounting surface of wall member 26, andhits and indents the impact sensitive primer tube 54 at ahigh velocityto cause deflagration of the'fulminating materiallocated therein andthus ignite the combustible foil 52.

Bar 72 may be retained in channel 86 by means of tabs 88 which projectfrom the top of channel 86 and overlie a portion of the bar 72. Theramps 81-85 do not dexed. Tabs 88 prevent the bar 72 from moving up outof channel 86 after some of the springs have been released and preventinadvertent spring release and consequent lamp flashing due to movementof the bar 72 if the array is dropped on its face.

To enable indexing of the slidable bar 72 in equal increments, eightevenly spaced ratchet drive teeth 90 are provided on a side of the baradjacent that on which the ramps are located. More specifically,referring to FIGS. 4-6, the ramps 81-85 aredisposed along the top of thebar 72, while the ratchet drive teeth 90 are located in the lower halfof the adjacent side of bar 72, as illustrated. The teeth 90 arerendered accessible to external actuating means through an aperture 92which extends through wall member 26 from its edge at the base 24 to theside of channel 86 (FIGS. 3 and 4). For example, translational indexingof the bar from left to right may be effected by a suitable actuatingmember 94 (FIG. 2) moving up'through the aperture 92 to engage one ofthe teeth and then moving laterally to the right to translate the bar 72along channel 86. More specifically, member 94 pushes bar 72 to theright a distance x determined by the length of aperture 92 and thespacing of drive teeth 90. This action causes one of the ramps on bar.72to lift its associated spring striker 68 over retaining catch 66. Theramp ends at this point,

and the released spring drvies the striker into a lamp primer, whichaction flashes that lamp. Member 94 is 'then disengaged from the ratchetdrive teeth by a downward movement and then moved laterally to the leftto ready it for the next indexing cycle. The square pattern of arrowsbelow actuating member 94in FIG. 2 illustrates this path of travel. In atypical application,

actuating member 94 may be part of a camera mechanism designed to enablethe photographer to flash a lamp in synchronization with the tripping ofa camera shutter to'take a picture.

The bottom of base 24 may be provided with suitable means for mountingthe photoflash assembly 10 on apcessive indexing ofthe slidable bar bymember 94.

Thus, for example, eight rapid'flash exposures may be taken with thecamera without the need for moving the lamps or rotating the unit. Thesequence of releasing the strikers in response to indexing is programmedby the number and respective locations of the ramps along the length ofthe slidable bar and the respective location of the spring strikers 68.In this case, five ramps on the bar 72 are arranged so that for aselected increment of translation along the channel 86, the bar travelwill cause a first ramp on that bar to release a strikerand a secondramp on that bar to be moved to a position adjacent another preenergizedstriker; This pattern of ramp positioning then continues'for allsuccessive x increments of translation until all, eight springs havebeen released.

For example, referring to FIGS. 25, according to one embodiment, thereare an equal number of evenly spaced strikers in each of the two rows ofsprings 4144 and 48. Typically, the common distance D between strikersin each row is equal to the distance between the corresponding lamps ineach row, which is determined by the lamp and reflector design. Thelength of the index increment'x is then based upon this'striker spac ingD and in the present case is equal to D/(n l), where n is the totalnumber of strikers. Hence, it may be stated that the common distance Dbetween strike-rs in each row is .t(n 1), where n is the total number ofstrikers in the two rows thereof (8) and x is the distance the slidablebar translates along the channel dur- 7 ing each indexing increment forrelease of a striker. ln

this instance, therefore, the spacing between strikers in each row is9.\'. It will be noted that the number of ramps equals n/2 l, which inthis instance is 5'. The

' first ramp 81' is adapted to release the first striker in wall member26 comprises a slot parallel to the side of channel 86 and having alength of 2):.

Thus, in FIG. 5, ramp 8! is positioned adjacent the striker spring 45,which is the first to be released in the firing sequence. Ramp 82 isspaced 7x from ramp 8] and, thus, is spaced a distance x from strikerspring 41 and a distance 2): from striker spring 46. Ramp 83 is spaced3x from strikerspring 42 and 4x from-striker spring 47. Ramp 84 isspaced 5x from striker spring 43 and 6x from striker spring48. The lastramp 85 is spaced distance 7x from striker spring 44. Accordingly, thespring release sequence will be: (1) spring 45 by ramp 81; (2) spring 41by ramp 82; (3) spring 46 by ramp 82', (4) spring 42 by ramp 83; (5)spring 47 by ramp 83; (6) spring 43 by ramp 84; (7)spring 48 by ramp 84;and (8) spring 44 by ramp 85. I

This ram'p arrangement requires no extension of the base to accommodatemovement of the release bar since the flash sequence moves in the samedirection as the movement of the bar itself, i.e., left to right asillustrated. The only travel space required is a minimum distance of 8xfrom the right end of the bar to the-right end of the channel. Hence,the minimum length imposed on channel 86 is x (n n 2)/2 and, thus, isdependent on the number of strikers (lamps) n and the striker spacing D,from which x is determined.

Referring to FIG. 5,-the new position of the slidable bar 72 is retainedafter eachindexing cycle by means of a detent mechanism, which maycomprise a spring loaded ball 98 engaging one of nine notches 100provided along the bottom of bar- 72. The spring loaded ball 98 isretained in a cylindrical cavity (not shown) provided in the wallmember26 at the bottom of channel 86. I

Accordingly, by virtue of the mechanical firing system, the rampprogramming, and the detent control,

the" present flash assembly'provides 'a self-contained memory function,whereby the next unused lamp in the flash sequence will always be readyfor immediate triggering, even thoughtlte unit may have been removedfrom a'camera and subsequently replaced. This is a sig- I nificantadvantage as compared to electrical arrays.

Although the invention has been described with respect toa specificembodiment, itwill be appreciated that modifications and changes may bemade by those skilled in the art without departing from the true spiritand scope of the invention. For example, the number of springs and lampsin the array may be varied, and the sliding bar could move from right toleft.

What I claim is:

l. A selective actuating mechanism for a photoflash lamp'array; saidarray including a support member, a

' plurality of percussively-ignitable flashlamps mounted .in twoparallel rows 'on saidsupport member, and a plurality of preenergizedstrikers mounted in two parallel rows on said support member, each rowof strikers being associated with a respective row of said flashlampsand each striker being individually releasable to fire a respective oneof said flashlamps; the selective I actuating mechanism comprising, incombination:

a longitudinal channel in said support member located between andparallel to said two rows of strikers;

a slidable bar retained in said channel; and,

means provided on said slidable bar for sequentially releasing saidpreenergized strikers to tire respective flashlamps of said array inresponse to successive indexing of said slidable bar along said channel.I

2. The mechanism of claim 1 wherein the sequence of releasing saidstrikers is programmed by the spatial disposition of said releasingmeans on said slidable bar and the respective location of said strikers.

3. The mechanism of claim 1 wherein said strikers are mounted so that,in the preenergized conditions, said strikers project beyond theperipheries of said channel to overlie a portion of said slidable bar,the strikers associated with one of said rows of lamps projecting in adirection opposite that toward which the strikers associated with theother row of lamps project.

4. The mechanism of claim 3 wherein said releasing means comprises oneor more ramps, and the sequence of releasing said strikers is programmedby the number and respective location of said ramps along the length ofsaid slidable bar and the respective location of said strikers. Y

5. The mechanism of claim 4 in which there are an equal number of evenlyspaced strikers in each of said rows of strikers, the distance betweenstrikers in each row is .r(n l), where n is the total number of strikersin the two rows thereof and x is the distance said slidable b'artranslates along said channel during each indexing increment for releaseof a striker, the number of said ramps equals n/2 l, the first ramp onsaid bar is adapted to release the first striker in one of said rows ofstrikers, the last ramp on said bar is adapted to release the laststriker in the other of said rows of strikers, each of the rampsintermediate said first and last ramps is, adapted to sequentiallyrelease twooppositely projecting strikers, each set of two oppositelyprojecting strikers to be released by one of said intermediate ramps isspaced apart by a distance x', and said ramps are evenly spaced apart bya distance of (n l)x.

6. The mechanism of claim 5 wherein the minimum length of said channelis x(n n 2)/2.

7. The mechanism of claim 1 further including a plurality of ratchetdrive teeth on said slidable bar which are engagable for indexing saidbar.

8. A photoflash assembly comprising, in combination a substantiallyplanar .base member;

a substantially planar wall member secured to said base member anddisposed substantially normal thereto, said wall member containing alongitudinal channel;

a plurality of percussively-ignitable flashlamps mounted in two parallelrows on the side of said wall member containing said channel with thelongitudinal axes of said lamps projecting parallel to said base member;

a plurality of preenergized strikers mounted in two parallel rows onsaid wall member with said longitudinal channel located between andparallel to said rows of strikers, each row of strikers being associatedwith a respective-row of said flashlamps and each striker beingindividually releasable to fire a respective one of said flashlamps;

a slidable bar retained in said longitudinal channel;

and

means projecting from said slidable bar and adapted for selectivelyreleasing said preenergized strikers;

to successive indexing to sequentially release said strikers by means ofsaid projecting means to fire respective ones of said flashlamps.

10. The assembly of claim 9 wherein the preenergized strikers mounted onsaid wall member project beyond the peripheries of said channel tooverlie a portion of said slidable bar, and said means projecting fromsaid slidable bar comprises one or more ramps linearly disposed alongone side of said bar, said sequence of releasing said strikers beingprogrammed by the number and respective location of said ramps along thelength of said slidable bar and the respective location of saidstrikers.

11. The assembly of claim 10 wherein said means accessible to be engagedfor indexing said slidable bar comprises a plurality of evenly spacedratchet drive teeth, said teeth being disposed on a side of said baradjacent that on which said ramps are located, and said aperture beinglocated on a side of said channel.

12. The assembly of claim 11 wherein there are an equal number of evenlyspaced strikers in each of'said rows of strikers, the distance betweenstrikers in each row is x(n l), where n is the total number of strikersin the two rows thereof and x is the distance said slidable bartranslates along said channel during each indexing increment for releaseof a striker, the number of said ramps equals n/2 l, the first ramp onsaid'bar is adapted to release the first striker in one of said rows ofstrikers, the last ramp on said bar is adapted to release the laststriker in the other of said rows of strikers, each of the rampsintermediate said first and last ramps is adapted to sequentiallyrelease two oppositely projecting strikers, each set of two oppositelyprojecting strikers to be released by one of said intermediate ramps isspaced apart by a distance x, and said ramps are evenly spaced apart bya distance of (n l)x.

13. The assembly of claim 12 wherein the minimum length of said channelis x(n n 2)/2.

14. The assembly of claim 10 wherein: each of said flashlamps has aprimer tube depending therefrom; said wallmember contains a plurality ofbores each for receiving the primer tube of a respective one of saidflashlamps to provide support therefor; and, each of said preenergizedstrikers is a portion of a folded torsion spring comprising asubstantially hairpin torsional section having two segments joined by abight, said striker portion projection from one of said segments, asupporting foot projecting from the other of said segments and fixedlymounted on said wall member, and a catch formed at the tip of said foot,said striker portion crossing said foot with said catch restraining saidstriker portion in a cocked condition.

15. The assembly of claim 14 further including an array of substantiallyconcave reflectors each disposed coaxially about a respective one ofsaid flashlamps, the optical axes of said reflectors being substantiallyperpendicular to said wall member and said reflectors all facing in onedirection away from the side of said wall member upon which saidflashlamps are mounted.

1. A selective actuating mechanism for a photoflash lamp array; saidarray including a support member, a plurality of percussively-ignitableflashlamps mounted in two parallel rows on said support member, and aplurality of preenergized strikers mounted in two parallel rows on saidsupport member, each row of strikers being associated with a respectiverow of said flashlamps and each striker being individually releasable tofire a respective one of said flashlamps; the selective actuatingmechanism comprising, in combination: a longitudinal channel in saidsupport member located between and parallel to said two rows ofstrikers; a slidable bar retained in said channel; and, means providedon said slidable bar for sequentially releasing said preenergizedstrikers to fire respective flashlamps of said array in response tosuccessive indexing of said slidable bar along said channel.
 2. Themechanism of claim 1 wherein the sequence of releasing said strikers isprogrammed by the spatial disposition of said releasing means on saidslidable bar and the respective location of said strikers.
 3. Themechanism of claim 1 wherein said strikers are mounted so that, in thepreenergized conditions, said strikers project beyond the peripheries ofsaid channel to overlie a portion of said slidable bar, the strikersassociated with one of said rows of lamps projecting in a directionopposite that toward which the strikers associated with the other row oflamps project.
 4. The mechanism of claim 3 wherein said releasing meanscomprises one or more ramps, and the sequence of releasing said strikersis programmed by the number and respective location of said ramps alongthe length of said slidable bar and the respective location of saidstrikers.
 5. The mechanism of claim 4 in which there are an equal numberof evenly spaced strikers in each of said rows of strikers, the distancebetween strikers in each row is x(n + 1), where n is the total number ofstrikers in the two rows thereof and x is the distance said slidable bartranslates along said channel during each indexing increment for releaseof a striker, the number of said ramps equals n/2 + 1, the first ramp onsaid bar is adapted to release the first striker in one of said rows ofstrikers, the last ramp on said bar is adapted to release the laststriker in the other of said rows of strikers, each of the rampsintermediate said first and last ramps is adapted to sequentiallyrelease two oppositely projecting strikers, each set of two oppositelyprojecting strikers to be released by one of said intermediate ramps isspaced apart by a distance x, and said ramps are evenly spaced apart bya distance of (n - 1)x.
 6. The mechanism of claim 5 wherein the minimumlength of said channel is x(n2 + n + 2)/2.
 7. The mechanism of claim 1further including a plurality of ratchet drive teeth on said slidablebar which are engagable for indexing said bar.
 8. A photoflash assemblycomprising, in combination a substantially planar base member; asubstantially planar wall member secured to said base member anddisposed substantially normal thereto, said wall member containing alongitudinal channel; a plurality of percussively-ignitable flashlampsmounted in two parallel rows on the side of said wall member containingsaid channel with the longitudinal axes of said lamps projectingparallel to said base member; a plurality of preenergized strikersmounted in two parallel rows on said wall member with said longitudinalchannel located between and parallel to said rows of strikers, each rowof strikers being associated with a respective row of said flashlampsand each striker being individually releasable to fire a respective oneof said flashlamps; a slidable bar retained in said longitudinalchannel; and means projecting from said slidable bar and adapted forselectively releasing said preenergized strikers; said slidable barbeing operative upon translation along said channel to selectivelyrelease said strikers in a predetermined sequence by means of saidprojecting means to thereby fire the respectively associated flashlamps.9. The assembly of claim 8 wherein said wall member has an aperturetherethrough within said channel, and further including means providedon said slidable bar which is accessible through the aperture in saidwall member to be engaged for indexing said slidable bar along saidchannel, said bar being operative in response to successive indexing tosequentially release said strikers by means of said projecting means tofire respective ones of said flashlamps.
 10. The assembly of claim 9wherein the preenergized strikers mounted on said wall member projectbeyond the peripheries of said channel to overlie a portion of saidslidable bar, and said means projecting from said slidable bar comprisesone or more ramps linearly disposed along one side of said bar, saidsequence of releasing said strikers being programmed by the number andrespective location of said ramps along the length of said slidable barand the respective location of said strikers.
 11. The assembly of claim10 wherein said means accessible to be engaged for indexing saidslidable bar comprises a plurality of evenly spaced ratchet drive teeth,said teeth being disposed on a side of said bar adjacent that on whichsaid ramps are located, and said aperture being located on a side ofsaid channel.
 12. The assembly of claim 11 wherein there are an equalnumber of evenly spaced strikers in each of said rows of strikers, thedistance between strikers in each row is x(n + 1), where n is the totalnumber of strikers in the two rows thereof and x is the distance saidslidable bar translates along said channel during each indexingincrement for release of a striker, the number of said ramps equalsn/2 + 1, the first ramp on said bar is adapted to release the firststriker in one of said rows of strikers, the last ramp on said bar isadapted to release the last striker in the other of said rows ofstrikers, each of the ramps intermediate said first and last ramps isadapted to sequentially release two oppositely projecting strikers, eachset of two oppositely projecting strikers to be released by one of saidintermediate ramps is spaced apart by a distance x, and said ramps areevenly spaced apart by a distance of (n - 1)x.
 13. The assembly of claim12 wherein the minimum length of said channel is x(n2 + n + 2)/2. 14.The assembly of claim 10 wherein: each of said flashlamps has a primertube depending therefrom; said wall member contains a plurality of boreseach for receiving the primer tube of a respective one of saidflashlamps to provide support therefor; and, each of said preenergizedstrikers is a portion of a folded torsion spring comprising asubstantially hairpin torsional section having two segments joined by abight, said striker portion projection from one of said segments, asupporting foot projecting from the other of said segments and fixedlymounted on said wall member, and a catch formed at the tip of said foot,said striker portion crossing said foot with said catch restraining saidstriker portion in a cocked condition.
 15. The assembly of claim 14further including an array of substantially concave reflectors eachdisposed coaxially about a respective One of said flashlamps, theoptical axes of said reflectors being substantially perpendicular tosaid wall member and said reflectors all facing in one direction awayfrom the side of said wall member upon which said flashlamps aremounted.